1. Field of the Invention
The present invention relates to the field of tool devices, and more specifically, to rotary sanders, hammers, chisels and the like.
2. Prior Art
The use of air impact hammers and similar devices is well recognized in the prior art. The benefit of such devices is that they can be driven by a source of compressed air thereby obviating the need for direct electric current, gas powered motor or other similar power sources. Inasmuch as many modern factories are equipped today with compressed air or other pneumatic fluid, air-driven devices have gained wide acceptance.
Examples of prior art devices which utilize air as a driving means for an impaction tool are shown in U.S. Pat. Nos. 2,722,918 and 3,344,868. In each of these references, there is disclosed a device which utilizes air pressure as a means for driving a piston so as to impact upon another member thereby enabling the device to act as a hammer or similar surface working tool. Problems with such devices are that they are relatively complex, and/or are difficult to manufacture. In addition, they appear to be directed to a specific utility. Thus, substantial reconfiguration is required in order to readily convert a device used for a hammer to, say, a chisel-type device, even though the action of a chisel and hammer are related.
A similar device to the air impact hammer tool is the rotary pneumatic powered sander which has likewise gained wide acceptance. Exemplars of similar prior art devices are disclosed in U.S. Pat. Nos. 2,570,009; 2,545,453; 2,946,315; 3,642,389 and 3,728,052. These references are directed to a wide range of different rotary pneumatic tools which utilize a rotary motor having a plurality of outwardly extending blades or vanes. Notwithstanding the development and a clear recognition of the advantages of such devices in the prior art, a number of shortcomings remain. As with the air impact hammer, the prior art rotary pneumatic sanders are relatively complex and/or difficult to manufacture. In addition, many of them use a complex venting system.
Thus, it appears that there has been a long felt need for pneumatic devices which are relatively straight-forward in their design, and thus can be easily manufactured. It is likewise clear from the prior art that a device which could utilize at least some of the same parts, whether the device was being used as an air impact hammer or as a rotary sander, would be very beneficial. These and other long felt problems are solved by the device of the present invention.